Boolean operation between a form and a spiral
What you need to do :

Select your spiral cube object, delete 2 faces so that it won't generate inner faces, apply both the Array and Curve modifier, press Alt &gt; Merge By Distance:



Fill each tip with F :



The topology of you shell is messy, go in Edit mode and press Alt &gt; Merge By Distance, in the Operator box choose a Merge Distance of 0,001 :



But you also need to delete inner faces, overlapping faces, and you need to recalculate the normals (AltN), especially if you plan to print in 3D.

Once everything done, you can merge all the faces of your shell surface, where the boolean is supposed to happen:




The Boolean will work fine: